possible from these data to decide exactly how many
days of faeces collection that is optimal, and the
conclusion must therefore be, the more days of
collection the more significant results. To emphasize
the importance of collection over a number of days,
we can take as an example the span of apparent
digestibility that was shown in our study during one
collection period, 0.235 at its lowest and 0.443 at its
highest, on P90.
Wu et al. (2000) demonstrated a linear relationship
between the amount of P consumed and excreted in
faeces when P intake ranged from about 60 to 120 g
day1. The present trial shows that this relationship is
linear over the wide range of 44 to 142 g day1 (Fig.
1). The slope of the regression indicates that for each
gram of increased P intake, 0.86 g would be excreted
in faeces. This value is higher than the value of 0.64 g
(Wu et al., 2000) when feed intake was adjusted to